(1) Field of the Application
The present application related to U.S. patent classification 416: FLUID REACTION SURFACES (I.E., IMPELLERS)
(2) Description of Related Art
Some prior art which was within those most similar, each contains one or some issues:                Difficult to self-start;        Engaging all including negative and excessive wind;        Half engaging half disengaging;        Lack of or not effective at over-load protection;        Lack of or not effective at over-speed protection.        